The Big Annemessex River is a 15.4 miles (24.8 km) tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the Chesapeake Bay

Chesapeake Bay

The Chesapeake Bay is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland and Virginia. The Chesapeake Bay's drainage basin covers in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West...

 on the Delmarva Peninsula

Delmarva Peninsula

The Delmarva Peninsula is a large peninsula on the East Coast of the United States, occupied by most of Delaware and portions of Maryland and Virginia...

. It rises in Kingston

Kingston, Maryland

Kingston is an unincorporated community in Somerset County, Maryland, United States. A small community at the head of navigation of the Big Annemessex River, it is located on Maryland Route 413 at the intersection of Kingston Lane...

, Somerset County

Somerset County, Maryland

-2010:Whereas according to the 2010 U.S. Census Bureau:*53.5% White*42.3% Black*0.3% Native American*0.7% Asian*0.0% Native Hawaiian or Pacific Islander*1.7% Two or more races*1.5% Other races*3.3% Hispanic or Latino -2000:...

, Maryland

Maryland

Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...

, and flows roughly southwest about 6 miles (10 km) in a meandering pattern, then widens into an estuary

Estuary

An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....

 and continues about 9 miles (14 km) to the bay, near Janes Island State Park

Janes Island State Park

Janes Island State Park is a state park in the state of Maryland. It is located in Somerset County, Maryland, on the Chesapeake Bay. The park features boat launch, canoe/kayak rental, cabins, camp fire programs, camp sites, camp store, dump station, fishing and crabbing, flat water canoeing and...

. Tributaries include Annemessex Creek, Holland Creek, Hall Creek, Muddy Creek, Colbourn Creek, Jones Creek and Daugherty Creek.

The river is spanned once by River Road, a residential county road far from any population center. The Annemessex Creek upstream, however, is spanned by Maryland Route 413

Maryland Route 413

Maryland Route 413 is a state highway in Somerset County in the U.S. state of Maryland. The route runs from a dead end at Crisfield's city dock, which is located on the Tangier Sound, northeast to U.S. Route 13 in Westover. It is the main highway leading into Crisfield, and is known as...

.

There is also a Little Annemessex River; the city of Crisfield

Crisfield, Maryland

Crisfield is a city in Somerset County, Maryland, United States, located on the Tangier Sound, an arm of the Chesapeake Bay. The population was 2,723 at the 2000 census. It is included in the Salisbury, Maryland Metropolitan Statistical Area...

rests upon its shores.